When a package container having liquid food such as milk, mineral water, tea, juice, soup, alcohols, or the like is produced, a web-shaped laminated packaging material is used, the packaging container is formed by sealing of a laminated packaging material with heat sealing, ultrasonic sealing and the like. For example, in a packaging and filling machine, first of all, strip is applied on an edge of web-shaped laminated packaging material, the laminated packaging material is formed in the shape of tube, both edges of the laminated packaging material and the strip which protects an inside end face of the longitudinal sealing part are pushed from the inside of the tube and are sealed in longitudinal direction (lengthwise) with a longitudinal sealing apparatus, the liquid-food-filled tube-shaped laminated packaging material is seals in transverse direction with a transversal sealing apparatus and is cut, a pillow-shaped preform container is formed, and the preform container is formed into predetermined shape, and a package container is completed.
FIG. 3 is a schematic perspective view showing an example of a packaging and filling machine. A reel of the web-shaped laminated packaging material 1 is in-fed into the packaging and filling machine. The laminated packaging material 1 comprises a flexible laminate of a paper substrate and polyethylene film laminated on both sides of the paper substrate, if necessary, a barrier layer of aluminum foil, gas barrier resin and the like is laminated between the paper substrate and the film, decorations are previously printed on the parts to correspond to the surfaces of packaging container 14.
The unwinded laminated packaging material 1 is continually conveyed with a feeder of the conveying means, and is conveyed through bending rollers and dancer rollers to a strip applicator 3, a strip 2 is attached in line with one edge of the laminated packaging material 1 with the strip applicator.
A pull-tab is attached, if necessary, with a pull-tab applicator on the laminated packaging material 1. The laminated packaging material 1 is conveyed to a sterilization bath 4, and is sterilized by sterilization liquid of hydrogen peroxide and the like in the sterilization bath 4. The laminated packaging material 1 is conveyed to an air knife 5 to be dried by the air knife 5, and is carried to the interior of sterile room 40. The laminated packaging material 1 is gradually transformed with forming rings 6, other forming rings into the tube shape.
The laminated packaging material 1 is preheated by hot air from a preheating means 8 of the longitudinal sealing apparatus to be sealed lengthwise, liquid food is filled from a bottom end of the filling pipe 7 into the tube-shaped laminated packaging material 1.
FIG. 4 shows an example of the modes of filling and controlling the liquid food to the predetermined liquid level from a filling pipe into the tube-shaped packaging material.
The perpendicular part of filling pipe 7 is prolonged underneath.
The upward part is connected to a control valve 32. A cylindrical float tube 34 is arranged circumferentially outside perpendicular part of the filling pipe 7. The float tube 34 floating in the liquid is located between the tube packaging material 1 and the filling pipe 7, and is put on the external surface of the perpendicularly part of the filling pipe 7 on top and bottom direction freely-movably. In float tube 11, an object to be detected 35 (magnet, transmitter or a tag) is installed. A detector 31 is disposed in the outside of the tube 1. The detector 31 converts changes of the strength and weakness of the signs with the object to be detected into currents, and outputs electrical signals.
When the liquid level is equal to the predetermined level or over, a stop signal is output, and an open signal is output to controller 33, when the liquid level is equal to the predetermined level or less. In the horizontal part of the filling pipe 7, electromagnetic flow control valve 32 is arranged, the electromagnetic flow control valve 32 is controlled by controller 33. The liquid level is controlled on the predetermined level.
The tube-shaped laminated packaging material 1 is guided with rollers, is carried in a transversal sealing apparatus 10, and is sandwiched to be sealed in the transverse direction. The transversal-sealed laminated packaging material is cut with a knif and the like, and pillow-shaped preforming containers 13 are formed.
The detailed partial cross section of transversal sealing apparatus 10 is shown in FIG. 5. In this embodiment, while the tube-like packaging material 1 is carried downward for a distance of the length corresponding to only one packaged container, it is held by pairs of forming flaps 41 and 41, and it is formed as an approximate container shape, the tube-like packaging material is held with pairs of seal jaws 10a, 10a and counter jaws 11, 11, two transversal seal zones are formed by the transversal sealing transversally, the middle of the seal zones of the connected pillow-like preforming bodies is cut by the knife 42, and separated pillow-like preformed bodies 13 are formed.
The preliminary container 13 is conveyed and is formed to the final shape by a final forming device 15, and a liquid-food filled packaged container 14 is produced.
In an example of the filling pipe, the filling pipe is fixed, an air pocket (hollow space) surrounding the filling pipe is sealed, while a packaging and filling machine is operating, a buffering member dampening movement of liquid food in the tube of the packaging material is comprised. (reference patent documents 4)    [patent documents 1] Japanese Utility Model Laid-Open No. 1-82102    [patent documents 2] Japanese Patent Laid-Open No. 10-167207    [patent documents 3] Japanese Patent Laid-Open No. 2004-098648    [patent documents 4] Japanese Patent Laid-Open No. 11-49105